In my events it just shows one picturelike this
And when i clicked into one it does this
What happens if you click on one of the dotted boxes on the second photo?
The picture thats meant to be there comes up
Back Up and try rebuild the library: hold down the command and option (or alt) keys while launching iPhoto. Use the resulting dialogue to rebuild. Include the option to rebuild the thumbnails. It can take 3 or 4 goes for this to work
Retrieving data ...